National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, 100050, China.
Chongqing Center for Disease Control and Prevention, Chongqing, 400042, China.
BMC Public Health. 2020 May 19;20(1):732. doi: 10.1186/s12889-020-08832-0.
The inverse association between physical activity and body fat percentage (%) varies among different populations. We aim to examine whether the significant association between them was uniform across the subpopulations after taking into account body mass index (BMI).
Our study relied on data from China Health and Nutrition Surveys in 2015, including 5763 participants aged 40-64 years from 15 regions. Physical activity was calculated as metabolic equivalent task hours per day (MET·h/d). Body fat% was measured by bioelectrical impedance analysis. Body mass index < 24 kg/m was defined as normal weight and BMI ≥ 24 kg/m was overweight/obese. The effects of physical activity on body fat% were estimated using the Kruskal-Wallis test among sex, age, BMI groups, education, income, region and urbanization. Quantile regression analyses were utilized to describe the relationship between physical activity and body fat% distribution.
Older adults, overweight/obese, higher education, higher income, residents of central China and those living in areas of higher urbanization had the lower physical activity. Participants who engaged in the highest level of physical activity had 2.0 and 1.5% lower body fat% than the lowest level of physical activity group (23.4, 34.8%) for men and women, respectively. There were 10.4 and 8.8% of normal weight males and females called normal weight obese. Overall, 1 h extra 4.5 MET•h/d was significantly associated with 0.079 and 0.110% less total body fat% at the 75th and 90th percentiles in normal weight males, with 0.071% less at the 25th percentiles in overweight/obese males, with 0.046-0.098% less at the 25th to 90th percentiles in normal weight females, and with 0.035-0.037% less from the 50th to 90th percentiles in overweight/obese females. The inverse association between physical activity and total body fat% was stronger in normal weight obese participants than other subgroups.
In middle-aged Chinese adults, the inverse association between physical activity and body fat% was only in particular subpopulations rather than the entire population. We should pay much attention to normal weight obese and give a suitable physical activity guideline taking into account people with different body fat%.
身体活动与体脂百分比（%）之间的反比关系在不同人群中存在差异。我们旨在研究在考虑体重指数（BMI）后，它们之间的显著关联是否在亚人群中保持一致。
我们的研究依赖于 2015 年中国健康与营养调查的数据，包括来自 15 个地区的 5763 名 40-64 岁的参与者。身体活动计算为每天代谢当量任务小时（MET·h/d）。体脂%通过生物电阻抗分析测量。BMI<24kg/m2定义为正常体重，BMI≥24kg/m2为超重/肥胖。使用 Kruskal-Wallis 检验在性别、年龄、BMI 组、教育、收入、地区和城市化水平之间估计身体活动对体脂%的影响。使用分位数回归分析描述身体活动与体脂%分布之间的关系。
老年人、超重/肥胖、较高的教育水平、较高的收入、来自中部地区的居民和居住在城市化程度较高地区的居民身体活动水平较低。与最低水平的身体活动组相比，从事最高水平身体活动的男性和女性的体脂%分别低 2.0%和 1.5%（23.4%、34.8%）。有 10.4%和 8.8%的正常体重男性和女性被称为正常体重肥胖。总体而言，正常体重男性在第 75 百分位和第 90 百分位，每增加 1 小时 4.5MET·h/d，总体脂%分别减少 0.079%和 0.110%，超重/肥胖男性在第 25 百分位减少 0.071%，正常体重女性在第 25 百分位至第 90 百分位减少 0.046%-0.098%，超重/肥胖女性在第 50 百分位至第 90 百分位减少 0.035%-0.037%。在正常体重肥胖参与者中，身体活动与总体脂%之间的反比关系强于其他亚组。
在中国中年成年人中，身体活动与体脂%之间的反比关系仅存在于特定亚人群中，而不是整个人群。我们应该更加关注正常体重肥胖人群，并考虑不同体脂%的人群，为他们提供适当的身体活动指导。
